汉江上游郧县庹家湾剖面光释光测年及意义  

OSL Dating of TJW Section in the Upper Hanjiang River Valley and Its Environmental Significance

作　　者：张文桐[1] 庞奖励[1] 黄春长[1] 周亚利[1] 查小春[1] 崔天宇[1] 王海燕[1] 杨丹[1] 

机构地区：[1]陕西师范大学旅游与环境学院,陕西西安710062

出　　处：《中国沙漠》2017年第5期885-892,共8页Journal of Desert Research

基　　金：国家自然科学基金项目(41271108;41371029);国家社会科学基金项目(14BZS070);中央高校基本科研业务费专项资金项目(201601006)

摘　　要：在野外考察基础上选择湖北郧县庹家湾剖面为研究对象。在对磁化率和粒度进行分析的同时,用单片再生剂量法进行了光释光测年(OSL)地层断代。OSL测年数据显示:剖面样品年龄处在55.11~13.57ka BP,且与地层深度呈现出良好的对应关系,此剖面为黄土风化堆积形成。黏粒含量、黏粒/粉砂值以及磁化率值等气候替代性指标数值在马兰黄土层228~260cm和294~370cm深度明显高于典型马兰黄土(L1),具有明显的成壤特征,通过OSL测年数据判断时间为27.26~21.59ka BP,说明在晚更新世时期气候并非持续稳定的寒冷干旱,而是具有一定的波动,在此期间气候相对温暖湿润,而且此次气候事件在黄土高原地区其他沉积记录中也有良好记录。On the basis of field investigations along the upper Hangjiang River valley,a typical loess-soil section was found at the Tuojiawan（TJW）.Magnetic susceptibility and particle-size distribution were measured in laboratory.OSL ages were measured by using the quartz single aliquot regenerative-dose protocol.The OSL results show that the optical ages of these samples ranged in 55.11-13.57 ka BP,showing agood relation with the depth in the TJW profile.It indicated that the profile was formed by loess weathering and accumulation.The content of clay,clay/coarse silt ratio,magnetic susceptibility in 228-260 cm and 294-370 cm were higher than those in Malan loess.The weathering intensity of this depth was obviously higher than that of Malan loess,close to the palaeosol（S0）,belongs to the weak palaeosol（L1-S1 and L1-S2）.The age range of L1-S1 and L1-S2 was 27.26-21.59 ka BP.The change of the indexes showed the climate and pedogenic environment changed since Pleistocene.It indicated there was a short time of warm and wet in the cold and arid glacial period（27.5-21.5 ka BP）,and the southeast monsoon gradually intensified during the early Holocene periods with the strongest monsoon in the mid-Holocene.

关 键 词：汉江 光释光测年 气候变暖 弱古土壤 

分 类 号：P531[天文地球—古生物学与地层学]